| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | Yes |
| Cracking (Shooting cracks)? | No |
Observation: Hatcher Pass
Location: Below Hatch/$1000 Run
Up-track towards Hatch/April Bowl, stopping at a bench below $1000 run. (Pin is at pit location)
Obvious signs of instability
Observer Comments
Visibility was in and out all day, but we saw the following avalanches from the past 24 hours:
Marmot: Multiple small crowns on SW aspect of Marmot - see photo below - likely from one slide that initiated near the peak. Several smaller crowns just to the south on the same aspect.
Skyscraper: Small crown on a SE aspect off the ridgeline towards Nixon's Nose - photo below.
4068': Small cornice fall it looked like over a North aspect, but light was flat.
Hatch: Several small loose snow avalanches on a North aspect, initiating around 3500' in steep rocks.
One IMPRESSIVE WHUMPH at the pit location. This was the sort of whumph where you notice a deformation of the snowpack and hear the propagation travel away from you... One additional fairly meh whumph in the creek bottom near the parking lot.
Rollerballs below 3000' on Marmot when we drove out - 4 PM.
Weather
Chased the promise of suckerholes today and had an hour of almost success midday with barely broken skies... but generally overcast or obscured.
Warm - 34 degrees at the parking lot (2900') - and probably not much below freezing up to 3900'...
Brief period of light snow in the afternoon at 3900'. Occasional light SE winds.
Snow surface
5-8" of new soft but dense snow!
Ski penetration ranged from 12" down low to 4-6" at 3900'.
Minor wind affect on the surface above 3500' on this route.
Winds have scoured some ridgelines, and $1000 run had some areas mid-run that appeared to be blown down to a crust layer overnight.
Moist surface by the 3 PM below 3000'
Snowpack
See pit below at the site of the impressive whumph. Probed from 3600' - 3900' and generally found 30 - 50cm of soft snow over the 12/26 crust, with total height of snow generally ranging from 110 - 160cm.
Crowns on Marmot SW face, from a slide that initiated near the top - similar small crowns were on the same slope to lookers right, between this gully and the next.
Small crowns off the ridge of Skyscraper, heading towards Nixon's Nose
Pit at the site of the impressive whumph; while the 12/26 crust is not buried as deep here, the place where the collapse initiated had 45cm of snow over the crust. (This location had collapsed in the whumph before tests were conducted.)
The suspected weak layer was a fairly thick layer of fist hard, very loose 1-3mm facets, delicately chained together. In this photo, the bottom half of the layer was carefully removed, leaving chains dangling!
Chained facets through the scope.
Pit location... and sky conditions when there was some limited visibility/light!